Technical Field
The present disclosure relates to an organic light-emitting display (OLED) device and an encapsulation structure.
Description of the Related Art
Display devices provide a variety of information graphically on a screen and are the core technology of information communications. Such display devices are becoming thinner, lighter, and easier to carry, along with higher performance. With such a trend, organic light-emitting display (OLED) devices are attracting attention, which control the amount of light emitted from an organic emission layer to display images.
An OLED device is a self-luminous device using a thin emission layer between electrodes, and thus the overall device can be made thinner. Further, an OLED device is not only advantageous in terms of power consumption by low driving voltage, but also has excellent color implementation, response speed, viewing angle, and contrast ratio (CR).
In a typical OLED device, a pixel drive circuit and an organic light-emitting element are formed on a substrate, and light emitted from an organic light-emitting element may pass the substrate or a barrier layer, thereby displaying images. The organic light-emitting element can easily deteriorate by internal factors such as deterioration of the electrodes and the emission layer due to oxygen or moisture, deterioration by the reaction between the emission layer and interface, etc., as well as external factors such as moisture, oxygen, ultraviolet rays, and processing limitations of the device. Among these, oxygen and moisture seriously affect the lifespan of the OLED device, and thus encapsulation of the OLED device is very important.
As one of the encapsulation techniques, there is a known method of sealing the space above an organic light-emitting element with a passivation layer, or providing a face seal, or employing an encapsulation plate. The face seal contains moisture absorbent material to absorb moisture permeating into the organic light-emitting element. The face seal is applied on the inner surface of the encapsulation plate, and then the encapsulation plate is attached to a pixel array substrate. After the face seal sandwiched between the two substrates attached together (the encapsulation plate and the pixel array substrate) has been cured, pressure exerted against the substrates is removed, such that an OLED device having the face seal structure is fabricated. The encapsulation plate may be made of glass, plastic, metal, or the like.